X-Git-Url: http://pilppa.org/gitweb/gitweb.cgi?a=blobdiff_plain;f=arch%2Fx86%2Fboot%2Fedd.c;h=1aae8f3e5ca1912b6eb60ad75e3c120af1110bed;hb=6925bac120097b823fc990c143b9789c21cc60b5;hp=d93cbc6464d0f8aa8aed3479b1b88a66993afa67;hpb=72a73693aac5ae82850cedc69fa5d264ca977c13;p=linux-2.6-omap-h63xx.git

diff --git a/arch/x86/boot/edd.c b/arch/x86/boot/edd.c
index d93cbc6464d..1aae8f3e5ca 100644
--- a/arch/x86/boot/edd.c
+++ b/arch/x86/boot/edd.c
@@ -41,6 +41,7 @@ static u32 read_mbr_sig(u8 devno, struct edd_info *ei, u32 *mbrsig)
 	char *mbrbuf_ptr, *mbrbuf_end;
 	u32 buf_base, mbr_base;
 	extern char _end[];
+	u16 mbr_magic;
 
 	sector_size = ei->params.bytes_per_sector;
 	if (!sector_size)
@@ -58,11 +59,15 @@ static u32 read_mbr_sig(u8 devno, struct edd_info *ei, u32 *mbrsig)
 	if (mbrbuf_end > (char *)(size_t)boot_params.hdr.heap_end_ptr)
 		return -1;
 
+	memset(mbrbuf_ptr, 0, sector_size);
 	if (read_mbr(devno, mbrbuf_ptr))
 		return -1;
 
 	*mbrsig = *(u32 *)&mbrbuf_ptr[EDD_MBR_SIG_OFFSET];
-	return 0;
+	mbr_magic = *(u16 *)&mbrbuf_ptr[510];
+
+	/* check for valid MBR magic */
+	return mbr_magic == 0xAA55 ? 0 : -1;
 }
 
 static int get_edd_info(u8 devno, struct edd_info *ei)